It was quiet in Nogales, Ariz., before the soldiers appeared. A line of armored vehicles rumbled through the morning stillness of the dusty border town, past its fading Old West–style storefronts and groups of curious locals who stepped into the autumn air to watch the convoy roll to a stop. American troops leaped to the pavement, clad in helmets, combat boots and camouflage fatigues. Wiping sleep from their eyes, the soldiers sized up their task: welding coils of razor wire atop the city’s 20-ft.-tall border fence with Mexico.

Everything felt out of place. The Army’s 104th Engineer Construction Company, based at Fort Hood, typically builds roads for hulking military vehicles in remote combat zones like Iraq and Afghanistan. But since Election Day, Nov. 6, they’ve been working on the border fence in Nogales, down the street from Kory’s bridal store. It isn’t a mission the troops are trained or equipped to do: the seven bulldozers, two excavators and other heavy equipment they hauled from central Texas have proved useless. Instead, they have been figuring it out on the fly, executing orders handed down by the Commander in Chief, President Donald Trump.

On one level, those orders seemed straight­forward: protect the U.S. against what Trump calls “an invasion” by a caravan of impoverished Central American migrants traveling north through Mexico. But the soldiers don’t plan to meet the caravan with force. In fact, they say, doing so would be illegal. Since the Posse Comitatus Act of 1878, the U.S. military has been forbidden to take part in domestic law enforcement. Instead, the 104th Engineer Construction Company is doing its best to provide planning assistance, engineering support, equipment and resources to the Department of Homeland Security.

Razor wire is used to help protect a shipping container holding guns and sensitive material.

Meridith Kohut for TIME

Soldiers eat dinner in the chow tent, where a Thanksgiving meal would be served, in Sunglow City, an outpost constructed in Tucson, Ariz.

Meridith Kohut for TIME

More than 100 units of heavy equipment, including armored Mine-Resistant Ambush Protected vehicles, sit parked, mostly collecting dust under the desert sun. There’s little chance they will be used here.

Meridith Kohut for TIME

Similar scenes have played out across the Southwest since Trump issued his orders on Oct. 26. Some 7,000 active-duty troops began to flood border communities from San Diego to Brownsville, Texas, a deployment that equals the troops fighting ISIS in Iraq and Syria. Not since the days when General John “Black Jack” Pershing pursued the Mexican revolutionary Pancho Villa in 1916 has a comparable number of active-duty soldiers converged along the southern frontier for a mission.

Trump is fond of saying you can’t be a country without a border. But what has the President’s ­deployment shown us about who we are as a nation in 2018? Three days of observing, talking and shivering with military units in Arizona shows a country not defined by its border but deeply divided by it: we remain uncertain about the place of immigrants in our communities, what’s needed to protect ourselves and how to apply our values to our politics.

The confusion comes at a price. The estimated cost of the border deployment is expected to total more than $220 million, U.S. officials say (outside estimates are somewhat lower). Critics deride the mission as a political stunt that served no purpose other than to rally Trump’s base ahead of the elections. “It’s a waste of time,” says Chuck Hagel, a former U.S. Defense Secretary, Republican Senator from Nebraska and Vietnam War veteran. “It’s clear to me that he’s using the military as political pawns, which is completely irresponsible.”

But the midterms are over now, Trump has stopped tweeting about the caravan, and the troops are still here, still out of place. On short notice, they flew from their bases to the border and built tent cities from nothing in the middle of nowhere. They established running water, electricity, working toilets. And they’re prepared to stay for weeks, patiently waiting, as the caravan inches closer and their own families celebrate Thanksgiving, and possibly Christmas, back home without them.

Helicopters fly over rapidly assembled tents used for army sleeping quarters.

Meridith Kohut for TIME

Responding to the caravan took on renewed urgency for Trump on Oct. 19, when he saw television footage of thousands of migrants storming Mexico’s border gate with Guatemala. By then, the President had grown increasingly agitated at the limits of his power to stop illegal crossings. His vision of forcing Mexico to fund a massive border-wall construction project was stymied first by geopolitical realities, and then by Congress. As the midterm elections approached, he was itching for a way to show voters he was tough on the border and to goad Democrats into a debate on immigration policy.

The images presented an opening. Trump demanded U.S. military officials come up with a plan to prevent something similar from happening at U.S. ports of entry, and midlevel officials at Homeland Security and the Pentagon began drafting a plan. On Oct. 25, Trump fired off a 6 a.m. tweet: “I am bringing out the military for this National Emergency. They will be stopped!”

The topic became a fixture at the President’s campaign rallies, where “Build the wall” made for a crowd-­rousing slogan and references to “birthright citizenship” reliably drew boos. National exit polls found the share of voters worried about immigration was about 23%, and Trump’s closing midterm argument targeted them, even as Republican strategists suggested he focus on the healthy economy instead. “At this very moment, large well-­organized ­caravans of migrants are marching toward our southern border. Some people call it an invasion,” Trump said Nov. 1, less than a week before Election Day. “These are tough people in many cases: a lot of young men, strong men and a lot of men that maybe we don’t want in our country.”

While members of the caravan rested their blistered feet in Mexico City in the first week of November, Trump ordered the U.S. military to fan out across the Southwest. Army Captain Charles Matthews, 40, had less than a week to prepare his troops for the deployment. Usually such orders come with four or five months’ lead time, but Matthews didn’t have that luxury. He tasked First Sergeant Brian Rethage, 40, with going through the company’s rolls and figuring out who was available to go. After weeding out those with medical or other issues, Rethage came up with about 130 deployable troops. Matthews broke the news to those soldiers: they were going to Arizona and might not be back in time for the holidays.

The next problem: deciphering what the mission was exactly. Unclear on the details, Matthews brought what he thought he might need: bulldozers, excavators, scrapers, rollers and graders, all loaded onto semitrucks and sent off on the 888-mile trek from Fort Hood to Davis-­Monthan Air Force Base in Tucson, Ariz. “We made an assumption that we would be doing horizontal earthwork: improving roads, you know, something in our wheelhouse,” he says. “We came out here and found we were wrong.”

It turned out the mission was to tighten security at two border locations in Nogales, the DeConcini Crossing and the Mariposa Crossing. The border fence splits the city in two: one side of town is in the U.S., the other is in Mexico. It’s made up of 20-ft. steel slats that snake up hills and down into valleys, running parallel to city streets. Instead of land movers and construction equipment, Matthews needed miles of razor wire, brackets to hang the wire from, welding machines to secure the brackets and construction lifts to get his soldiers up and down.

Getting the material and equipment was just the start. Only eight of 130 troops knew how to weld. (“By design,” he says. “My company is not trained to weld.”) The baskets on the cherry pickers used to lift the soldiers to the top of the fence weren’t suitable for the work, so the troops had to construct new ones from discarded wooden pallets. Then the team realized the sparks from the welder were falling on taxis parked behind the fence, on the Mexican side of the border. So Matthews’ troops draped a 12-ft.-long wet rag from the basket to swallow the sparks. “This is a nonstandard engineering mission,” Matthews says. “But we’re engineers. We solve problems.”

From sunrise to sundown, the company welded the brackets and affixed the razor wire, under the watch of bemused residents. In the past, the fence never stopped the people of Nogales from moving back and forth across the border for shopping, ­doctors appointments, family visits or daily work. The locals have a saying: “Ambos Nogales.” In English it means “Nogales Together.” But the presence of the troops underscored the permanence of the fence and what it has come to represent.

Soldiers train in combat lifesaving techniques at Sunglow City, the newly erected Army outpost in Tucson, on Nov. 13.

Meridith Kohut for TIME

Soldiers pass their downtime by throwing a football around, texting their partners, exercising or waiting for the outdoor mess hall to open.

Meridith Kohut for TIME

Each day, the migrant caravan trudges nearer. It began in the Honduran city of San Pedro Sula on Oct. 12 and reached the Mexican capital nearly four weeks later, populated by migrants traveling through rain and heat. The caravan’s 5,000 ­people—many of them parents, children and unaccompanied ­minors—say they are fleeing violence and poverty in Central America. They travel together because there’s safety in numbers: migrants have been kidnapped, raped or even killed. Two other, smaller caravans have since formed to follow the first. Many members will split from the group in Mexico. Others will travel the remaining miles to reach the U.S. border and apply for asylum.

To some in Nogales, they would be welcome. It is ironic, officials there say, their city needs more, not less, traffic from Mexico right now. Trump’s crackdown has slowed the number of people crossing the border into Nogales to a trickle. In the past 10 years, annual pedestrian crossings into Nogales have dropped to 2.7 million from 7.7 million. That lack of foot traffic has resulted in the closure of some 15 stores in and around Morley Avenue, the city’s main commercial drag, the officials say.

Santa Cruz County supervisor Bruce Bracker closed his family’s retail shop in 2018; it had been open for 94 years. He argued that the years-long Border Patrol staffing shortages at Southwest ports of entry posed the largest security threat to border towns, such as Nogales. “The connotation of razor wire in our city is depressing. It looks like a prison,” Bracker says. “I get that illegal immigration is a problem. It needs to be addressed. But America is supposed to set an example for the world on these sorts of issues. Shutting down asylum claims and deploying the military to the border isn’t the solution. It’s the beginning of another problem.”

Military police stand guard as other members of the 104th Engineer Construction Company work to heighten security of the border wall.

Meridith Kohut for TIME

The members of the 104th Engineer Construction Company avoid such ­debates. They aren’t the only troops on hand. Military police stand ready to defend the engineers should something go awry. But they don’t anticipate facing any enemy other than the weather, the fragility of their equipment or the lure of fast-food restaurants. “We’re not here to stop the migrant caravan,” says Colonel Larry Dewey, commander of the 16th Military Police Brigade from Fort Bragg, N.C. “We’re here to make sure they come through in an orderly manner.”

The Nogales detachment is part of a 1,500-troop deployment in Arizona. Most of them are stationed 75 miles from Nogales at Davis-­Monthan Air Force Base, where they’ve constructed a 77-sq.-acre outpost called Sunglow City. That base, if you squint hard enough, is indistinguishable from ones like it in Iraq or Afghanistan, a logistical feat sprawled across the desert. The Army spread 1,700 tons of gravel over an area that features 140 tents, 150 portable toilets, a 20-bed hospital, a gym, laundry service and eight trailers packed with 15 hot showers each. Soldiers can watch TV while they wait their turn.

Cpt. Jacob Riffe, 29, from Augusta, Ga., puts his shoes on after waking up just after dawn inside his unit's tent.

Meridith Kohut for TIME

Soldiers of the 104th Engineer Construction Company weld brackets for concertina wire along the border wall.

Meridith Kohut for TIME

If it feels like a base on the other side of the world, it’s not. Every day, the troops are reminded they’re deployed deep in their own homeland. Restaurants and bars just outside the base gates are off-limits ­because the soldiers are considered to be on a deployment. Some younger soldiers have been overheard complaining that they are prohibited from going off base to eat at a nearby Chili’s. The Army plans to serve the troops a Thanksgiving dinner—with turkey and trimmings provided by contract caterers—on the base at Davis-Monthan. Soldiers will phone home or Skype with their loved ones. Some are single parents; their children will mark the holiday back home with temporary guardians.

Those who have served in combat operations overseas know any comparison to the ongoing wars is laughable. “This isn’t a deployment,” says Staff Sergeant Tamara Bonner, 38, of Fayetteville, N.C., who served in Iraq and Afghanistan. “We’re carrying out a mission, but this isn’t a deployment.”

Nearby, more than two dozen heavily armored vehicles, including Mine-Resistant Ambush Protected vehicles, sit parked, collecting dust under the desert sun. There’s little chance they will be used here. Troops in Sunglow City often find themselves with little to do. They fill the time throwing a football around, texting their girlfriends, exercising or waiting for the outdoor mess hall to open. But experienced Pentagon hands on base recognize one group that has profited from the vehicles’ dispatch to Sunglow City: the private contractors who were paid to haul them there from Texas.

A soldier walks through a sandstorm at Sunglow City.

Meridith Kohut for TIME

Back in Nogales, the soldiers are making steady progress on the wall. Three days after U.S. soldiers started putting up the razor wire in Nogales, their work was put to the test. On Nov. 9, a Mexican man tried jumping the fence through a gap in the wire. U.S. Border Patrol agents immediately responded. The man tried to scramble back over the wall but got entangled in the newly emplaced coils, U.S. Customs and Border Protection confirmed to TIME. As the Border Patrol agents closed in, the man freed himself and made it back into Mexico.

When the mission was announced Oct. 29, it was called Operation Faithful Patriot. Nine days later, the Pentagon quietly scotched that name, wary of its political overtones. It’s now officially known as Operation Secure Line, but privately, some soldiers are jokingly calling it “Operation Border Security”—or Operation B.S.

The U.S. military still doesn’t know which port of entry the caravan is headed for. And even if it comes to Nogales, it’s not clear the work of the 104th Engineer Construction Company will have been for any purpose. On Nov. 14, Defense Secretary James Mattis and Homeland Security Secretary Kirstjen Nielsen visited soldiers working the border mission in Donna, Texas. A soldier there asked Mattis whether they would later have to tear down the razor wire that they put up just days earlier. Mattis replied, “We’ll let you know.” —With reporting by Brian Bennett and Philip Elliott/Washington

“I remember the day after the Election, a friend of mine who happens to be white, remarked on social media that he “finally wasn’t embarrassed of America and our President.”

I sprained my eyes rolling them and they have never fully recovered.

Since then I’ve heard this sentiment echoed by more white folks than I can count, especially in recent months; supposed relief at once again having a leader who instills pride.

Since I don’t have the time to ask each of the individually, I’ll ask here:

So, you were embarrassed for the past 8 years, huh?

Really?

Whatexactlywere you embarrassed by?

Were you embarrassed by his lone and enduring twenty-five year marriage to a strong woman he’s never ceased to publicly praise, respect, or cherish?

Were you embarrassed by the way he lovingly and sweetly parented and protected his daughters?

Were you embarrassed by his Columbia University degree in Political Science or his graduating magna cum laude from Harvard Law School?

Maybe you were embarrassed by his white American and Black Kenyan parents, or the diversity he was raised in as normal?

Were you embarrassed by his eloquence, his quick wit, his easy humor, his seeming comfort meeting with both world leaders and street cleaners; by his bright smile or his sense of empathy or his steadiness—perhaps by his lack of personal scandals or verbal gaffes or impulsive tirades?

No.Of course you weren’t.

Honestly, I don’t believe you were ever embarrassed.That word implies an association that brings ridicule, one that makes you ashamed by association, and ifthat’ssomething you claim to have experienced over the past eight years by having Barack Obama representing you in the world—I’m going to suggest you rethink your word choice.

You weren’t “embarrassed” by Barack Obama.

You were threatened by him.You were offended by him.You were challenged by him.You were enraged by him.

But I don’t believe it had anything to do with his resume or his experience or his character or his conduct in office—because you seem fully proud right now to be associated with a three-time married, serial adulterer and confessed predator; a man whose election and business dealings and relationships are riddled with controversy and malfeasance.You’re perfectly fine being represented by a bullying, obnoxious, genitalia-grabbing, Tweet-ranting, Prime Minister-shoving charlatan who’s managed to offended all our allies in a few short months.And you’re okay with him putting on religious faith like a rented, dusty, ill-fitting tuxedo and immediately tossing it in the garbage when he’s finished with it.

None of that you’re embarrassed of?I wonder how that works.

Actually, I’m afraid I have an idea.I hope I’m wrong.

Listen, you’re perfectly within your rights to have disagreed with Barack Obama’s policies or to have taken issue with his tactics.No one’s claiming he was a flawless politician or a perfect human being.But somehow I don’t think that’s what we’re talking about here.I think the thing President Obama did thatreallyupset you, white friend—was having a complexion that was far darker than you were ever comfortable with.I think the President we have now feels much better.

Because objectively speaking, if what’s happening in our country right now doesn’t cause you great shame and doesn’t induce the continual meeting of your palm to your face—I don’t believe embarrassment is ever something you struggle with.

No, if you claimed to be “embarrassed” by Barack Obama but you’re not embarrassed by Donald Trump—I’m going to strongly suggest it was largely a pigmentation issue.

And as an American and a Christian committed to diversity and equality and to the liberty at the heart of this nation—that, embarrasses me.”

It is still dark out when Border Patrol agent Herman Rivera’s radio crackles to life. His fellow agents, posted nearby on levee roads above the Rio Grande, report movement along the border with Mexico in the dim predawn. As the first rays of sunlight creep across the horizon, the team bursts into action, charging down into the scrub, dodging bushes and ducking under low-hanging branches in pursuit of migrants. Helicopter blades whomp overhead.

“I’ve got one over here,” an agent yells from a field where stalks of sugar-cane tower over his head. “I’ve got two over here,” screams another. They emerge a beat later with a line of men in handcuffs. Elsewhere, agents discover four more migrants, three from China and one from Guatemala, hiding in thick underbrush.

But not all of those who come across the border with Mexico run or hide. Hours later, as the sun reaches its midday peak, Rivera stands overlooking the river, watching as two men climb into an inflatable raft and paddle toward the U.S. shore. He doesn’t call for backup—there will be no need to chase these two. They approach Rivera’s truck, smiling broadly. They are a father and son, both named Fredy, they explain. They’ve been traveling for 13 days from Nicaragua and say they can’t go back. In the simple words of those fleeing their homes in search of security—a language as old as human history itself—they ask for asylum in America.

For Rivera and the U.S. immigration system he serves, the Fredys pose a more complicated challenge than many of the others detained that morning. Those caught crossing the border in search of work, looking to reunite with family members or smuggling contraband face a legal process that is relatively swift and noncontroversial. In most cases, they’re arrested, listed for expedited deportation and sent back to their home country without fanfare. But as asylum seekers, families like Fredy and Fredy qualify for a fair hearing under a decades-old refugee law.

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The number of asylum seekers has skyrocketed. In 2008, according to federal data, fewer than 5,000 people apprehended by border agents expressed fear of returning home, thereby triggering the asylum process. Ten years later, that number has soared to more than 97,000—a nearly 2,000% increase. The figure has doubled in the past two years alone, driven by the arrivals of families and unaccompanied minors.

Some immigration-rights advocates explain this uptick by pointing at world events—environmental devastation, gang activity and political volatility in much of Central America. They say that the U.S., a nation founded by religious refugees, is built on a proud tradition of sheltering those facing persecution and that we should make room for as many as we can, whatever the source of their fear.

President Donald Trump and many of his supporters see things differently. They argue that our asylum laws are being exploited, that the migrants who file for refugee status are only pretending to flee oppression as a way to sneak into the country through a legal back door. “[Asylum] is an escape hatch from the laws that Congress has passed regulating immigration,” says Mark Krikorian, executive director of the Center for Immigration Studies, a think tank that advocates for lower immigration.

The Trump Administration is waging a policy war against asylum seekers. Its first big move was the family-separation policy that was designed to deter -asylum-seeking families. In June, former Attorney General Jeff Sessions narrowed the U.S. asylum criteria to disqualify victims of gang or domestic violence. In October, the Trump Administration ordered thousands of active-duty troops to Texas, California and Arizona to confront a so-called caravan of Central Americans, including many likely asylum seekers, who are making their way by foot to the border. In November, Trump issued a new rule that will bar all migrants for 90 days from seeking asylum if they do not come through designated ports of entry.

The political drama has fueled a deeper, more unsettling debate that gets to the heart of what kind of a country America wants to be. On the right, immigration hard-liners promise to vanquish migrant “invaders,” while on the left, activists threaten, in a snowballing hashtag campaign, to #AbolishICE in its entirety, a reference to U.S. Immigration and Customs Enforcement. Almost imperceptible beneath the shouting are two questions that—if the country were able to figure out how to answer them—could settle the fight: To whom should America give asylum, and how can we humanely and responsibly grant it to them, while denying it to others?

For now, those questions will be temporarily addressed in court and on the border. Immigrant-rights activists say Trump’s latest policy moves are not just cruel but illegal. A day after the White House announced the latest rule change, a coalition led by the American Civil Liberties Union filed suit to block it—the latest of many suits levied against the Administration on behalf of asylum seekers this year. And every morning, from Texas to California, border agents will scramble to keep up. “It doesn’t matter if we deploy a wall or a fence or bring in more helicopters—-this group of people is turning -themselves in to us,” says Manuel Padilla Jr., chief of the Rio Grande Valley Sector and a 34-year veteran of the Border Patrol. “This situation is not sustainable.”

Miriam Castillo Castillo, next to her young niece, speaks with a border officer after crossing the river to McAllen on Sept. 25; members of their group said they were fleeing politically motivated violence at home.

John Francis Peters for TIME

A short drive from Rivera’s post at the border, a stream of migrants, wearing GPS-tracking ankle bracelets, file into the Rio Grande Valley Humanitarian Respite Center, which is run by the nonprofit Catholic Charities in McAllen, Texas. This group of exhausted migrants is made up of family units, like the two Fredys, and all have sought asylum. Slumped into rows of blue plastic chairs and clutching bags emblazoned with the words Department of Homeland Security, they are at the beginning of a long process—one that’s become vastly more complicated over the past 80 years.

Until the 1940s, the U.S. did not have a policy governing the admission of would-be refugees: -federal laws didn’t distinguish between immigrants and asylum seekers. But after World War II left 7 million people uprooted in Europe, U.S. lawmakers were forced to act. In 1948, Congress passed the Displaced Persons Act, opening America’s immigration door to some 350,000 refugees from Europe over the next four years. In 1967, the U.S. signed the U.N. refugee protocols, voluntarily committing to protections for refugees.

Those protocols define refugees as people who are outside their country and afraid to return because of a well-founded fear of persecution based on religion, race, nationality or membership in a particular social or political group. But refugee status was for decades granted unequally through loopholes and exceptions to politically sympathetic groups, like those fleeing communist regimes in Hungary or Cuba, or escaping the crisis created by the Vietnam War. It wasn’t until the Refugee Act of 1980 that Congress created a comprehensive system for granting asylum in the U.S. If the criteria outlined in the U.N. refugee protocol were met, any applicant could be welcomed in the U.S.

Migrants who crossed the Rio Grande into McAllen are approached by a border officer on Sept. 25.

John Francis Peters for TIME

Members of a group of migrants from China and Guatemala unlace their shoes before being taken into custody, after illegally crossing the border through the Rio Grande, on Sept. 25.

John Francis Peters for TIME

In practice, that system often kicks in when people like the Fredys come face to face with immigration authorities and express a fear of returning to their home country. A trained U.S. official then interviews them to judge whether their fears are believable. In fiscal year 2018, roughly 89% of asylum seekers passed this initial “credible fear” screening, according to federal data. But the odds narrow from there. Asylum seekers are assigned a date to plead their case in immigration court, which imposes a high burden of proof. This year, judges granted asylum in only 17% of cases decided in immigration court where migrants had passed credible-fear interviews.

What happens to asylum seekers who are not granted refugee status? That’s where the political fight really heats up. The Trump Administration says the problem is that after asylum seekers pass their credible-fear interviews, they are released from custody to await their date in immigration court—a -system Trump calls “catch and release.” With a backlog of 791,821 cases, new court dates are often months or years in the future. In fiscal year 2018, immigration judges completed just over 34,000 cases originating with a credible-fear referral, according to federal data. In nearly a third of those cases—10,534—migrants failed to show up at their scheduled court hearing.

Krikorian, the immigration hard-liner, sees evidence of bad faith at every stage of the asylum process. “Half of the people who say they have a fear and want to apply for asylum never bother after they are let go into the country,” he says. From 2008 to 2018, 53% of migrants who submitted to a credible-fear interview actually filed for asylum, according to federal data. He also claims that some who do apply for asylum expect to be denied but can benefit in the meanwhile: if more than 180 days elapse without a decision on a migrant’s immigration case, the migrant becomes eligible for a work permit. “They know they are going to be turned down,” he says, “but they get a year or two in the U.S. while they’re working.”

Padilla, the longtime Border Patrol chief, argues asylum seekers should be held in detention until their court date. The population of asylum seekers “keeps growing exponentially because they’re actually being released into the community,” he says. Sessions has made a similar case, suggesting that releasing immigrants as they pursue asylum claims creates “incentives for illegal aliens to come here and claim a fear of return.” In October, Trump told Fox News that he would build “tent cities” to house migrants until they could face a judge. “We’re going to put tents up all over the place,” he said.

A border officer pats down a migrant from Honduras who had illegally crossed from Mexico to McAllen on Sept. 25.

John Francis Peters for TIME

The Rio Grande Valley Sector, which stretches over 34 counties and 34,000 sq. mi. of southeast Texas, is patrolled by a small army of roughly 3,000 Border Patrol agents. Over the years, many have grown accustomed to the flow of unauthorized immigration by studying the variegated landscape, honing their tracking skills and swapping advice. After patrolling a section of the river, Rivera says, agents will sometimes pull piles of tires behind their trucks to refresh the ground so it’s easier to spot the dusty footprints. He tells a story of identifying a group of ostensible joggers as undocumented migrants by a telltale necklace that one of them wore.

Still, the job of a Border Patrol agent remains Sis-yphean. In October, agents arrested 50,975 migrants along the southwestern border—23,121 were family units, marking the highest one-month total on rec-ord. But as much as hard-liners may want to arrest all of them, immigration lawyers and advocates argue that prolonged detention of asylum seekers simply won’t work. They admit detention can deter some migrants, but only at great cost. First, the ACLU has argued in lawsuits that the prolonged detention of asylum seekers violates both a 2009 ICE directive and the U.N. Refugee Convention. Second, detaining more asylum seekers is expensive. On average, it costs $319 per person per day to detain migrant families, according to DHS. With long wait times for court dates, that will add up. Releasing migrants with ankle monitors and enrolling them in case–management programs have proved to be cheaper and more effective than detention. The Trump Administration ended one such initiative in 2017.

Perhaps the most important issue, advocates say, is that the prolonged detention of asylum seekers is immoral. Many travel as families with young children and babies. Do Americans really want to become a nation that jails hundreds of thousands of impoverished families in makeshift camps along its southern border because a portion, if released into the country, might not go through the court system to test their asylum claims?

As it turns out, both political parties bear some blame for the current mess. The crisis arguably began in 2014, under President Barack Obama, when an influx of unaccompanied minors and families crossed the southern border. The flow has increased under Trump. But instead of boosting funding to hire the many more immigration judges and administrators necessary to efficiently process asylum seekers, Trump and Obama focused disproportionately on immigration enforcement. That may have earned both Presidents political chits among rule-of-law voters, but it didn’t do much to expedite the asylum process or address the root of the problem, says Doris Meissner, director of the Immigration Policy Program at the Migration Policy Institute.

One straightforward way to stem the current influx of asylum seekers, Meissner says, would be to streamline the immigration bureaucracy. The U.S. should publicize a clear definition of who qualifies for asylum, what criteria will be considered in hearings and an explanation of what it takes to prove your case for refugee status. The Justice Department, Meissner says, should bolster immigration courts so they can judge asylum claims more quickly and fairly and eliminate the case backlog. A broken immigration–justice system leaves migrants vulnerable and “invites misuse” of the system, she says.

A trafficker returns to the Mexican side of the Rio Grande after paddling over two Nicaraguans on Sept. 25.

John Francis Peters for TIME

Paying for more judges and other immigration officials will be expensive, advocates admit, but less so than other politically motivated solutions, like sending thousands of active-duty U.S. troops to the southern border. To counter the migrant caravan, which is expected to arrive at the border this month, Trump has already deployed 5,600 troops, according to Defense Department officials, and he has promised up to 15,000 total. The Center for Strategic and Budgetary Assessments, an independent analysis group, -estimated that such an effort will likely cost $42 million to $110 million.

Eleanor Acer, senior director of refugee protection at Human Rights First, says any lasting solution to the migrant crisis should also address the root of the problem: poverty, violence and instability in the countries from which many of these people are fleeing. “Until the human-rights abuses and violence and deprivations and underlying issues are addressed, people will continue to flee their countries,” she says. “We actually have to deal with the problems that are causing people to leave their homes.” She recommends investing in jobs, economic development and other long-term foreign-aid programs.

Back in the Rio Grande Valley Sector, Padilla, the longtime border agent who calls for detaining asylum seekers until their court hearings, agrees that any viable solution should deal with all the sources of the problem. It’s not enough to scare people into not coming to the U.S., he says. “There have been efforts, Band-Aid efforts, to deal with this population during both Administrations,” he says, referring to the Obama and Trump presidencies. “But immigration reform has not happened to really deal with it.”

Until that solution comes, agent Rivera says, he and his colleagues will continue doing the work they do, monitoring the thickets at dawn, walking the riverbank and arresting and processing the migrants they find. At the end of a long, warm afternoon, Rivera’s radio comes alive again. An agent’s voice crackles over the line. A family of five have been caught crossing the border, he says. They have asked for asylum. Rivera speeds to the scene.